Unknown Worlds was one of many black and white magazines Marvel put out in the seventies to compete with similar magazines from Warren and other publishers. This one featured original and adapted Science Fiction stories. Other stories from this issue include an adaption of Larry Niven’s “Not Long Before The End” by Doug Moench and Vicente Alcazar, Frank Herbert’s “Occupation Force” adapted by Gerry Conway and George Pérez and original stories by Bruce Jones and Tony Isabella & Gene Colan.
The contents page describes the Ellison story the following way:
The Hugo- and Nebula-winning tale of a funny man – in a most unfunny future! Harlan Ellison’s most celebrated story.